A Wideband 28-GHz Transmit–Receive Front-End for 5G Handset Phased Arrays in 40-nm CMOS

This paper reports a transmit-receive (Tx-Rx) front-end (FE) in bulk CMOS targeting fifth-generation (5G) mobile user equipment (UE)-phased arrays. Block-level specifications are first reviewed based on link budget and UE array beam steering considerations, and compared against measured standalone power/low-noise amplifier and phase shifter test circuit performances. Then, the codesign of the Tx-Rx switch and antenna impedance matching is investigated for the important case of wideband dual-resonance networks, leading to a proposed topology that is experimentally verified using silicon passive test structures. A fully integrated FE prototype is fabricated in 1.1-V 1P6M 40-nm bulk CMOS and characterized in detail across digital gain and phase settings. Measurements show Tx-mode P1 dB/PAE1 dB ≥ 14.6 dBm/21.9% across 27-30 GHz, and peak Pout/PAE = 6.5dBm/8.8% at 27 GHz for an 8 x 100-MHz carrier-aggregated 64-QAM OFDM signal. In Rx-mode, a noise figure of 5.5-6 dB and an input-referred third-order intercept point of -8.5 to -6 dBm are achieved across 27-33 GHz. Normalized to area/power consumption, the achieved performance is the state of the art relative to the most recent CMOS/SiGe FEs.